| 摘要 |
PURPOSE:To improve the low concentration at a black part of an original as well as the reproducibility of continuous gradation when a double-color copy of black and another color A is wanted, by setting the potential of a latent image at the part of color A higher than that of the black color part. CONSTITUTION:When a double-color copy is wanted from a double-color original of black and another color A, a photoreceptor is used. This photoreceptor includes a photosensitive layer 2 having the sensitivity to the visible beam region including the color A and a photosensitive layer 3 having no sensitivity to the A color beam and transmitting the A color beam. Then the electric charging and the image exposure are carried out to the photoreceptor to form the electric charge patterns corresponding to the black color part and the A color pat. After this, the uniform exposure is given to the photoreceptor which the A color beam. As a result, the potential of a latent image is set higher at the color A part than the black color part. In such way, both the low concentration of the black color part and the reproducibility of continuous gradation are improved for an original. |
